This section is intended to provide information relevant to understanding various technologies described herein. As the section's title implies, this is a discussion of related art that should in no way imply that it is prior art. Generally, related art may or may not be considered prior art. It should therefore be understood that any statement in this section should be read in this light, and not as any admission of prior art.
Generally, in physical design, performance and reliability at advanced process nodes may be limited by legal requirements of a standard cell library. For instance, in the case of a standard cell library, which may not have a defined well or substrate ties inside standard cells, designers may be required to tie N-type wells to a highest potential (e.g., a source potential, such as VDD) and further tie the substrate (or P-type wells) to a lowest potential (e.g., ground potential, such as GND or VSS) before performing place-and-route (PnR) using a well tap cell. Further, well tap structures may include an N-type tap formed by an N-type well, an N-type implant, and an active region and a P-type tap formed by a P-type well, a P-type implant, and another active region. Next, the N-type and P-type taps may then be connected or coupled to appropriate voltage potential (e.g., VDD, VSS) using metal wires and contacts/vias. Generally, in reference to the standard cell library, these types of structures should be realized within a minimum possible area.
In reference to physical design, FIG. 1 illustrates a diagram of a conventional implant structure for a cell 100 as known in the art. In particular, FIG. 1 refers to a conventional implant structure for well taps using conventional island style well taps 120, 122. As shown in FIG. 1, an N-type well region may be implanted with a P-type implant and an N-type island 122, and further, a P-type well region may be implanted with an N-type implant and a P-type island 120. As further shown in FIG. 1, the cell 100 may include active regions coupled to different potentials VSS, VDD via metal wires and contacts/vias.